hello. i have a 6x2x2 sump filtered tank.. i filled it up to the very top of the weir 3 days ago now the water is halfway down the weir i could not find a leak? so could it be evaporation? the heaters are in the sump and half of it is not covered the tank is covered and there is alot of condensation on it. it has been doing this for maybe a 2 months now., it is winter over here in australia.. the tank is uneven ( not level ) as are all of my tanks ( floor is insanly uneven) although i use styrofoam between the tank and the stand,.. could this split a seam? PLEASE HELP ME!! im in desperate need of advice